List of companies of Ireland

This is a list of notable companies based in Ireland, or subsidiaries according to their sector. It includes companies from the entire island. The state of the Republic of Ireland covers five-sixths of the island, with Northern Ireland, part of the United Kingdom, covering the remainder in the north-east. Each has separate regulatory and registration authorities.

Public limited companies, which carry the suffix "plc" or "cpt" and whose shares may be listed on a stock exchange. Where this is the case, it is noted in this article.

Company Limited by Guarantee, this type of company has members, not shareholders, as such generally limited to trade associations and not-for-profit bodies.

Companies in the Republic of Ireland must be registered with the Companies Registration Office, and comply with the provisions of the Companies Acts. Companies in Northern Ireland must be registered with the Department for the Economy's Companies Registry. Certain Northern Ireland organisations are dealt with on a UK-wide basis and are dealt with by Companies House.

Some entries on this list may be statutory corporations - a business form governed by a board appointed by an Irish Government minister under a particular piece of legislation - not formally companies as such, but are effectively treated as such and are included on this list as they are usually large business. For more details on this form of governance, see state-sponsored bodies of Ireland.

Multinational industrial conglomerate manufacturing electronics for the automotive industry and commercial electrical equipment. After a full merger with Tyco International in 2016, the firm established headquarters in Cork, Ireland.

Global professional services and management consulting firm. The company formed as a spin-off from Arthur Andersen in 1989 and moved their headquarters to Dublin in 2009. Accenture's clients more than three-quarters of the Fortune Global 500.

Multinational medical device design, development and manufacturing. company. After acquiring Dublin-based Covidien in 2014, the firm moved their headquarters to Ireland while retaining operational headquarters in Fridley, Minnesota.